Try to include the number of hands you have on the players in their stats, it's important. That guy seems to play many hands but doesn't seem that aggressive, i wouldn't be surprised if you only had a few hands on him, he might not be a real maniac and turn out to be a calling station instead with 70/8/1 or so in the next orbits.

You are out of position and 2 people have already coldcalled UTG's raise, you should make your 3bet even bigger, like between $4.5 and $5 is fine. UTG won't really care about the size of your 3bet anyway, and you don't really want the others to stick around.

On the flop it's better if you have a vague idea of what sort of hands that guy likes to play, and whether he will peel your c-bet with overcards or not. Semi-bluffing both maniacs and calling stations isn't really something you should be looking forward to as they will call or raise you with garbage, so just giving up and waiting for the next opportunity where you do actually flop a hand is ok, especially if you're not comfortable playing the rest of the hand should they continue.

Once you do c-bet and he calls we have no idea what he could have and whether he'll fold to a turn bet or bet himself if we check. You pick up the nutflush redraw with 2 overcards but the 7c on the turn makes both a flush and a 4-straight on board, along with multiple two pairs hands. With no clue how much fold equity you have i don't think bet/calling your redraw here is gonna show a profit unless you know more about your opponent, so giving up is fine. c/call if he gives you odds to draw, otherwise c/fold.